Good Lawyer Guide's response

Contact the lawyer who acted for you on the conveyancing, when you bought the house. Put the problem to that lawyer and ask for an opinion.

Almost certainly, the sellers will have completed Property Enquiry forms which they will have signed, and which will then have been sent to your solicitor (and probably to you). Those Enquiry forms will have asked them about the condition of the property and whether or not they know of any defects. They may have given an evasive answer, or maybe they gave an untruthful answer. If the answer was definitely untruthful (eg because they knew of the dry rot but concealed it) then you will probably have a claim against them. On the other hand, if the answer was simply evasive (eg they said you should rely upon your own surveyor’s report) then you are unlikely to have a claim.

If the sellers genuinely did not know about the dry rot, then you will almost certainly not have a claim against them.

In practice, it is only if you can show that they gave a wrong reply to the Property Enquiry form that you will have a chance of claiming off them.